# [HIGH] CISA warns of max severity Ubiquiti flaws exploited in attacks

**Source:** BleepingComputer
**Published:** 2026-06-24
**Article:** https://www.bleepingcomputer.com/news/security/cisa-warns-of-max-severity-ubiquiti-flaws-exploited-in-attacks/

## Threat Profile

CISA warns of max severity Ubiquiti flaws exploited in attacks 
By Bill Toulas 
June 24, 2026
10:35 AM
0 




The U.S. Cybersecurity and Infrastructure Security Agency (CISA) is warning of hackers actively exploiting flaws in Ubiquity UniFi OS and Lantronix serial-to-ethernet servers.




According to the BOD 26-04 directive , federal agencies have three days to apply available security updates or vendor-recommended mitigations.




 




The Ubiquiti flaws that CISA added to its catalog of Know…

## Indicators of Compromise (high-fidelity only)

- **CVE:** `CVE-2026-34908`
- **CVE:** `CVE-2026-34909`
- **CVE:** `CVE-2026-34910`
- **CVE:** `CVE-2025-67038`

## MITRE ATT&CK Techniques

- **T1190** — Exploit Public-Facing Application
- **T1486** — Data Encrypted for Impact
- **T1003.001** — LSASS Memory
- **T1003** — OS Credential Dumping
- **T1021.002** — SMB/Windows Admin Shares
- **T1569.002** — Service Execution

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Ransomware-style mass file rename / extension change

`UC_RANSOM_ENCRYPT` · phase: **actions** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count, dc(Filesystem.file_name) AS files
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("modified","renamed")
    by Filesystem.dest, Filesystem.user, _time span=1m
| `drop_dm_object_name(Filesystem)`
| where files > 200
| sort - files
```

**Defender KQL:**
```kql
DeviceFileEvents
| where Timestamp > ago(1d)
| where InitiatingProcessAccountName !endswith "$"
| where ActionType in ("FileRenamed","FileModified")
| summarize files = dcount(FileName) by DeviceName, InitiatingProcessAccountName, bin(Timestamp, 1m)
| where files > 200    // empirical: > 200 unique-file renames in 1m by one account on one host
                       //            is well above the P99 of legitimate bulk-tooling
| order by files desc
```

### LSASS process access / dump (credential theft)

`UC_LSASS` · phase: **actions** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where (Processes.process="*lsass*" OR Processes.process="*sekurlsa*"
        OR Processes.process="*MiniDump*" OR Processes.process="*comsvcs.dll*MiniDump*"
        OR Processes.process="*procdump*lsass*")
       OR (Processes.process_name="rundll32.exe" AND Processes.process="*comsvcs*MiniDump*")
    by Processes.dest, Processes.user, Processes.process_name, Processes.process, Processes.parent_process_name
| `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where ActionType == "OpenProcessApiCall"
| where FileName =~ "lsass.exe"
| where InitiatingProcessFileName !in~ ("MsSense.exe","MsMpEng.exe","csrss.exe",
                                          "svchost.exe","wininit.exe","services.exe",
                                          "lsm.exe","SearchProtocolHost.exe")
| project Timestamp, DeviceName, ActionType, FileName,
          InitiatingProcessFileName, InitiatingProcessCommandLine,
          InitiatingProcessFolderPath, AccountName
| order by Timestamp desc
```

### Remote service execution — PsExec / SMB lateral movement

`UC_LATERAL_PSEXEC` · phase: **actions** · confidence: **High**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where Processes.process_name IN ("psexec.exe","psexesvc.exe","paexec.exe","smbexec.py")
       OR (Processes.process_name="wmic.exe" AND Processes.process="*/node:*")
    by Processes.dest, Processes.user, Processes.process_name, Processes.process, Processes.parent_process_name
| `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where FileName in~ ("psexec.exe","psexesvc.exe","paexec.exe","smbexec.py")
   or (FileName =~ "wmic.exe" and ProcessCommandLine has "/node:")
| project Timestamp, DeviceName, AccountName, FileName, ProcessCommandLine, InitiatingProcessFileName
| order by Timestamp desc
```

### IOC-driven hunts (use shared templates)

These are standard IOC-substitution hunts — the canonical SPL and KQL live once in [`_TEMPLATES.md`](../_TEMPLATES.md), so we don't repeat the same boilerplate on every CVE / hash / network-IOC briefing.

- **Asset exposure — vulnerability matches article CVE(s)** ([template](../_TEMPLATES.md#asset-exposure)) — phase: **recon**, confidence: **High**
  - CVE(s): `CVE-2026-34908`, `CVE-2026-34909`, `CVE-2026-34910`, `CVE-2025-67038`


## Why this matters

Severity classified as **HIGH** based on: CVE present, 4 use case(s) fired, 6 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.